1. Field of the Invention
Methods and apparatuses consistent with the exemplary embodiments relate to a display apparatus and calibration method therefor, and more particularly, to a display apparatus for performing calibration using a calibrator, and a calibration method therefor.
2. Description of the Related Art
There is a phenomenon where color information moves or brightness changes due to the color characteristics, electrical characteristics, or optical characteristics of a display apparatus even when the same color needs to be expressed. Such a phenomenon is called spatial non-uniformity. In general, brightness may change up to 40% in a display apparatus.
Meanwhile, in a professional monitor or a broadcasting reference television, the uniformity characteristics of a display apparatus are extremely important elements. In the case of a broadcasting reference television, the required uniformity is 95% or more. Due to the optical, electrical, and physical characteristics of the current display apparatuses (liquid crystal display (LCD), plasma display panel (PDP), organic light emitting diode (OLED), etc.), there is a significant cost associated with satisfying the required specifications, and thus a method to solve this problem through signal processing is needed.
Signal processing can be used to measure the brightness through an external calibrator, and to perform non-uniformity correction using the measured information.
In such a case, the entire display size of the pertinent local area is displayed in order to measure relevant data, such as the color coordinates and brightness of the pertinent local area, for non-uniformity correction. A user places the calibrator in the center of the pertinent local area by eye measurement and measures the data.
Herein, if a sensor of the calibrator is not placed where the user intends to measure, the sensor is rendered unable to perform an exact non-uniformity correction. In particular, there is at least one specific case where it is impossible to measure the edges due to apparatus characteristics of the calibrator.
FIGS. 1A to 1D are views which illustrate several problems of the conventional art.
FIG. 1A is a view illustrating the nonconformity relationship of a calibrator and a measuring position when performing a non-uniformity correction on a local area of 5×5.
According to FIG. 1A, a situation may occur where the calibrator is caught on a bezel of a display screen, making it impossible to measure the data.
In this case, as illustrated in FIG. 1B, the user must rotate the calibrator 180° for an exact measurement.
In addition, as illustrated in FIG. 1C, another situation may occur which presents a problem that the greater the number of the local areas, as, for example, in a local area of 7×7, the greater the number of various angles to which the user must rotate the calibrator to perform an exact measurement.
Further, if a general user is required to figure out the position of the calibrator, as illustrated, for example, in FIG. 1D, and rotate the calibrator every time to perform a measurement in the center of the pertinent local area, additional problems of increased inconvenience for the user and reduced exactness of the measurement tend to arise.